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A cold tap is rarely a dead boiler. Five checks, taken in order, identify most causes before you pick up the phone — and make the call shorter when you do.
The direct answer: read the boiler's pressure gauge — cold, it should sit around 1 to 1.5 bar, and a low reading is topped up once via the filling loop — then check the timer and thermostat are actually asking for hot water, and check nothing has tripped at the consumer unit. If the heating runs but the taps stay cold, say exactly that when you call 020 4577 2888 — it points at one specific part.
If you smell gas at any point, stop the checks. Leave the property, do not operate light switches or use naked flames, and call the National Gas Emergency Service on 0800 111 999 from a safe distance. And a hard boundary for everything below: none of it involves opening the boiler casing. Work behind the casing on a gas boiler is legally a job for a suitably qualified engineer — ask whoever attends whether they are Gas Safe registered for it.
Before suspecting a fault, rule out the controls. More cold showers are caused by clocks and switches than by broken machinery, and these checks cost nothing.
Low pressure is the most common reason a boiler refuses to make hot water, and it announces itself on the front of the machine.
This split is the most diagnostic pattern on the page, and which kind of system you have decides what it means.
In a Forth valley cold snap, a modern condensing boiler has one well-known weak point: the small plastic condensate pipe, which often runs outside and can freeze solid. The boiler then gurgles, locks out and refuses to run — the fault will clear once the pipe is thawed. If you can reach the frozen external section safely at ground level, warm (never boiling) water or a warm cloth on the pipe usually frees it; reset the boiler once afterwards. If it is out of reach, or the lockout returns, report it exactly. Falkirk's housing mix matters here too — older terraces and post-war stock often carry cylinders and tanks, newer estates mostly combis — so tell the plumber which arrangement you have. The right van stock differs for each, and the two systems fail cold in entirely different ways.
On a combi boiler that split usually points at the diverter valve or a sensor — the part that switches the boiler between radiators and taps — rather than a dead boiler. On a home with a cylinder, check the cylinder thermostat and the timed hot water schedule first. Either way, the pattern narrows the fault: say exactly which half works when you call.
Once, yes. Cold, most sealed systems sit around 1 to 1.5 bar; if the gauge reads below 1, top up via the filling loop following the manual for your model. If the pressure falls again within days, stop topping up and have the loss traced — repeated refills feed the fault rather than fixing it.
If your home has a hot water cylinder with an immersion heater, yes — it heats the cylinder with its own electric element, independently of the boiler, and makes a reasonable stopgap. It costs more to run than gas, so treat it as a bridge, not a fix. If the immersion produces hot water when the boiler cannot, that fact itself helps the diagnosis.
No. Everything on this page happens outside the casing — the gauge, the display, the filling loop, the controls. Work behind the casing on a gas boiler must legally be done by a suitably qualified engineer, and it is reasonable to ask whoever attends whether they are Gas Safe registered for that work.
Stop checking anything. Leave the property, do not operate light switches or use naked flames, and once you are at a safe distance call the National Gas Emergency Service on 0800 111 999. Only go back inside when you have been told it is safe.
The main page — how the line works and the areas covered.
Go to home →Gauge readings, lockouts, error codes — and gas safety.
Read the guide →Stopcock, taps, electrics — the sequence, in order.
Read the guide →Gentle thawing from the tap end back — and prevention.
Read the guide →Damp patches, dropping pressure — the test that settles it.
Read the guide →One fixture or the whole house — the test that tells you.
Read the guide →How pricing is structured and what to ask before work starts.
Read the guide →Describe what you found — gauge, controls, which taps — and be connected with a local plumber covering Falkirk and the surrounding towns, any hour.
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